Converts a video to a gif

convert.sh

#!/bin/bash -e

# Converts a video to a gif

if [ "$#" -ne 2 ]; then
    echo "usage: ${0##*/} [input video] [output gif]"
    exit 1
fi

VIDEO=$1
GIF=$2

# finds width and height of $VIDEO expressed as 123x456
WIDTH_HEIGHT=$(ffprobe -loglevel warning -show_streams $VIDEO | grep -e "width\|height" | sed -E 's/(width|height)=//g' | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/x/g')

# converts the video
ffmpeg -i $VIDEO -s $WIDTH_HEIGHT -r 10 -f gif - | gifsicle --optimize=3 --delay=3 > $GIF